Method of manufacturing bobbins, particularly film bobbins



June 25, 1935. v P. SC HWARZ 2,006,281

METHOD OF MANUFACTURING BOBBINS; PARTICULARLY FI LM BOBBINS Fi'led Nov. 25, 1932 I o I i V m. i .191

\ I I x Patented June 25, 1935 UNITED STATES PATENT OFFICE Philipp Schwarz, Wuppertal-Barmen, Germany Application November 25, 1932, Serial No. 644,358 In Germany December 1, 1931 .10 Claims. (Cl. 29-470) 10 accompanying drawing.

In the accompanying drawing, like characters of reference indicate like parts in the several views, and:-

Figure l is a side elevation of a completed bobbin constructed in accordance with this invention.

Figure 2 is an end elevation showing one end of such bobbin.

Figure3 is an end elevation showing the other end of said bobbin.

Figure 4 is a section illustrating the first step in the production of a flange end for such bobbins.

Figure 5 is a section illustrating a second step in the production of such a flange end and showing one end of the bobbin tube in full lines ready for attachment and in dotted lines in the position it assumes prior to the next step in the operation.

Figure 6 is a section showing the final step in the operation and the method of effecting the same.

Figure 7 is a view somewhat similar to Figure 5 but showing a modified arrangement of flange.

Figure 8 is a view similar to Figure 4 but showing a second modified arrangement of flange.

Figure 9 is a viewsimilar to Figure 5 but showing said second modification.

Figure 10 is a section showing the final positions .of the parts when united by the method of this second modification.

Figure 11 is a view similar to Figure 5 but showing a third modification of the method.

Figure 12 is a view similar to Figure 6 but showing said third modification.

Figure 13 is a view similar to Figure 11 but showing a fourth modification of the method used.

Figure 14 is a view similar to Figure 10 but showing the completion of the connection over this fourth modification.

The film bobbin in accordance with Figs. 1 to 3 consists of a tubular bobbin core a and the two flanges b and c situated at the end of the core. The bobbin tube a may be made to consist of a strip of sheet metal so bent as to form a cylindrical tube. It may also have two longitudinal slots d situated opposite each other, provided for the purpose of introducing the end of the paper band carrying the film strip. The two flanges b, c are each made from a circular disk of sheet 5 metal, the outer edge of which, for the purpose of reinforcement, may be turned over so as to form a bead. One flange b is provided with a circular opening and is intended for the reception of the spindle on which the bobbin revolves. The 10 other flange 0, however, has a key slot 9. It serves for the reception of the spindle key by which the bobbin is rotated. The edges of the circular opening I in the flange .b and of the enlarged central part of the slot g in the flange c are pressed inwardly so as to form necks constituting a reliable guide to position the bobbin on the spindle and the key.

The bobbin tube a is secured to the two flanges b, 0. According to Figs. 4 to 7 this is efiected in the manner described in the following. For the sake of simplicity only the attachment of one flange. b to one end of the bobbin tube a has been represented in these figures. The flange c at the other end of the tube end is secured in exactly the same manner.

The central part of the flange b, the area of which is slightly in excess of the cross section of the tube a is made to assume the shape of a hat I by subjecting said central part to a process of drawing or pressing, the open side of said hat being situated on the inner side of the flange. Round this hat-shaped part i, also by means of a pressing process, a crease 2 projecting towards the inside of the flange and having a conical outer wall is formed, with the result that the flange is made, in the first instance, to assume the shape shown in Fig. 4. Subsequently the top of the hat-shaped central part of the flange l is provided with an indentation 3, the walls 4 of which are cone-shaped and that in such a manner, that the major base of the conical frustum is situated on the outside of the flange. The bottom 5 of this indentation could, of course, be level, but in connection with film bobbins it has proved of advantage to be inclined downwardly in an outward direction; On providing the indentation 3 the wall lw of the hat-shaped part i will be widened to a slight extent and thereby made to assume a somewhat conical position identical with that of the wall 4 of the indentation 3 (see Fig. 5). The bobbin flange is now provided with the hole 1 or g intended for the reception of the pivot or of the key. This is effected by punching a hole in the bottom 5 of the indentation 3 in the first instance, afterwards drawing the edge of the hole 1 or of the slot g inwardly to a certain extent. The flange b is now prepared and ready to be secured to the bobbin tube. In this condition the flange has an annular channel to receive the tube end.

The bobbin tube a requires no preparation for the purpose of securing the flange thereto. An ordinary bobbin tube may be made use of for this purpose, provided it is perfectly cylindrical from end to end and has been squarely cut ofi at the ends.

The connection between the bobbin tube a and the flange b is now effected in such a manner, that the flange is placed upon the end of the tube, the two parts now being pressed together in an axial direction. This will cause tube end a to be forced into the crease formed by the wall I a of the hat-shaped flange part I and the wall 4 of the indentation provided in the top of said hat-shaped flange part, thereby widening the conical wall 4 (see the part shown in dotted lines in Fig. 5). after, the widened tube end a together with the channel surrounding the latter, is turned over in an outward direction. At the same time, the crease 2, projecting towards the inside of the flange, is bent inwardly and forced back into the plane of the flange, whereby it is pressed closely against the bobbin tube or even slightly into the wall of the tube, being slightly cor stricted thereby. The final shape of the flange and tube end will then be identical with that shown in Fig. 6. It is of course obvious to those skilled in the art that this operation of. forcing the crease 2 inwardly results in crimping the tube, which is in marked contradiction to merely bending the channel outwardly which does not result in crimping the tube.

The pressing-in of the tube end into the channel 4 and the turning over of the tube end and crease in an outward direction, as well as the bending inwards of the crease 2 may be efiected successfully by axial pressure. In connection herewith a tubular die 6, surrounding the bobbin tube, pressed inwardly against the flange, and an outer die I pressing the hat-shaped part I, is used as has been shown in Fig. 6. At the other end of the bobbin tube a the flange will be secured in exactly the same manner, as previously mentioned. In connection therewith it will, however, be possible to secure both flanges to the bobbin tube a in one operation, by placing the two flanges on the two tube ends and by causing two dies to exert pressure from the outside on their hat-shaped central parts I. Immediately following thereon, the widened tube ends together with the folds or creases enclosing the former, are turn d over, whilst simultaneously the channels are bent over in an inward direction and presse l against the bobbin tube a by means of two dies exerting pressure on the flange from within. The inner dies 6 enclosing the tube a require, of course, to be split lengthwise, so as to render it possible to remove them from the tube again after the flanges have been secured.

It will be seen, that the provision of the channel projecting towards the inner side of the bobbin flange embodies the advantage, that the fold or channel, formed by the wall Ia of the hatshaped part I of the flange and by the wall 4 of the channel pressed into the flange, and enclosing the turned-over tube end a extends close Immediately thereto the jacket of the bobbin tube a, thus possessing a considerable depth, so that a comparatively long piece of the tube a is folded and clamped into the flange. In this way a reliable connection between tube and flange is formed and that eyen if the diameter of the tube a, as in the example, is less than the inside width of the. hat-shaped part I of the flange. Owing to the fact, that in the top of the hat-shaped central part I. an indentation with a conical wall is provided by means of the pressing process, the connection is made, that the fold or channel formed by the walls Ia and 4 together with the widened tube end, is turned over in an outward direction merely by simple axial pressure, with the result that neither-will be upset or distorted. Furthermore, this design possesses the advantageous feature, that the tube end, when pressed into the channel, will be automatically widened. It will thus be unnecessary to widen the tube by means of a special operation prior to the attachment of the flanges'and thus a simple tube, cylindrical over its whole length, can be employed. The manner of providing the holes I, g'for the pivot and the key only after the other required formation I of the flange has been completed, above all, after the indentation 3 has been provided in the top of the hat-shaped central part I, embodies the advantage, that the holes will not be changed or distorted in regard to their shape in consequence of later or subsequent working operations to which the flange is subjected. In connection with the edging or turning over of the tube end,

taking place after the' tube has been pressed into the flange, and of the fold or channel enclosing the tube end, no deformation of the bottom of the indentation 3 will take place, but this bottom will rather be' displaced parallel to itself in the axial direction of the bobbin.

Instead of employing bobbin tubes cylindrical over their entire lengths, such bobbin tubes may also beemployed, the ends of which have been previously widened soas to be frusto-conical. In this case the pressing-in of the indentation 3 into the top of the hat-shaped central part I of the flange may be omitted, rendering it possible to secure the bobbin flange to the tube end in the form as shown in Fig. 4. In connection therewith the flange with its hat-shaped central part I is placed upon the widened tube end and the part I upset in such a manner, that the tube end, together with the wall Ia of the hatshaped flange part is turned over in an outward direction, whereby the tube end, situated between this wall and the top of the hat-shaped middle part I, is clamped in. Simultaneously the wall projecting towards the inner side of the flange is bent in an inward direction and pressed against the wall of the tube.

The method represented in Figs. 4 to 6 may also be modified in accordance with Fig. 7 in that the sequence of the separate working steps or phases is changed. In such case the channel formed by thewall Ia of the hat-shaped central part and the wall of the indentation 3 is turned over in an outward direction already pr or to the attachment of the flange to the tube end, whilst the crease 2 projecting towards the inside of the flange is bent in an inward direction or pressed back into the plane of the flange. The flange will thus be given from the very beginning that 6. In conjunction with this mode of shaping the flange the attachment to the tube is effected in such a manner, that the cylindrical tube end is pressed into the fold or channel turned in an outward direction, in connection with which it is successively widened and turned over in an outward direction corresponding to the shape of the fold 4, I already turned over, so that again the final shape of flange and tube is attained as shown in Fig. 6. The entire process of attachment in accordance with this modification thus merely consists in pressing the tube end into the fold. If required, the fold may be subjected to a final pressure immediately after pressing the tube end into the fold or crease 4, I, in order to cause the latter to close tightly round the turned over tube end a thus holding the tube end in the fold absolutely-tightly. This finalpressure is not, however, absolutely necessary.

In the method in accordance with Figs. 8 to 10, the channel projecting towards the inner side of the flange of the example of performance in accordance with Figs. 4-6 is replaced by the entire part of the flange b situated outside the hatshaped central part I and having the shape of a truncated cone; (Fig. 8). The top of the hatshaped central part I is again provided with an indentation 3 with a cone-shaped wall 4. The bottom of said indentation is provided with the hole intended for the reception of the spindle or the key. (Fig. 9.) The flange thus formed is placed with its hat-shaped part upon the end of the bobbin tube, whereupon, by exerting an axial pressure on flange and tube, the tube end a is pressed into the channel and consequently widened. Immediately in connection herewith, the channel together with tube end a is turned over in an outward direction, whilst at the same time the outer flange part b, having the shape of a truncated cone, is pressed into a flat or level shape. It will be seen from Fig. 10, that the edge of the aperture 2a of the hat-shaped flange part i is tightly pressed against the bobbin tube a or even constricting said tube in its wall, so that again a reliable connection between flange and tube is furnished.

The sequence of the working operations of this example of performance may also be varied somewhat similarly as described in connection with Fig. 7, inasmuch as prior to the attachment of the flange to the end of the bobbin tube a the fold formed by the walls and *3 may be turned over in an outward direction, and the outer flange part b is pressed into a fiat form. This will produce a flange, the shape of which essentially corresponds to that in accordance with Fig. 7. For the purpose of attaching the flange to the tube, it is only required to press the tube end into the turned over channel, causing the tube end to be widened and to be formed in an outward direction. The mode of attachment is, therefore, identical with that described in connection with Fig. 7. Furthermore, in connection with this method a bobbin tube, the ends of which have previously been conically widened, may be employed in place of the tubes cylindrical from end to end. The pressing of the indentation 3 into the bottom of the hat-shaped flange part I may then be dispensed with and 'the flange can be attached or secured to the tube end in the form shown in Fig. 8. The procedure in connection herewith is such, that the flange with its hat-shaped central part is placed upon the widened tube end and the part i pressed down in such a manner, that the tube which forms the inner wall of the channel.

end together with the wall Ia of the hat-shaped flange part is turned over in an outward direction, whereby the tube end will be clamped in between this wall and the top of the hat-shaped part I. At the same time the cone-shaped flange part is made to assume a level or flat shape, whereby the edge of the aperture of the hatshaped part is tightly pressed against the bobbin tube or even caused to constrict the wall of the tube.

In the method in accordance with the Figs. 11 and 12 the hat-shaped central part I is displaced towards the inside of the flange, so that it forms, together with the fold or crease 2 enclosing it, a kind of collar on the inside of the flange. It is obvious, that in connection therewith the flange b has been provided with a channel of greater depth than that in the example of performance in accordance with Figs. 4 to 6. The central part I of the flange situated within said channel is made to assume the shape of a hat, the wall 4 of The top 5 of the hat-shaped flange part I is slightly curved in the centre and provided with a hole I or g intended for the reception of the spindle or the key for actuating the bobbin, in connection with which the edge of the hole is forced in an inward direction (Fig. 11).

The bobbin tube a, being cylindrical from end to end,is placed in the hat-shaped central part I of the flange, the top 5 of this flange part is provided with a groove 31: possessing a cone-shaped outer wall 4. The outer wall 4 of this groove forms, together with the inner wall of the groove to of the hat-shaped part i a channel enclosing the tube end, said channel being bent over in an outward direction together with the tube end a causing the latter to be tightly clamped in the channel. When pressing in the groove the curved central part of the top 5 is displaced, parallel to itself, axially to such an extent. that it does not project over the fold. At the same time as the groove Walls are pressed in and the channel formed thereby is bent in an outward direction, the inner wall of the channel is bent inwardly and thereby so pressed against the bobbin tube a, that its wall will be constricted, so that now the channel edge will engage the constriction 3 of the tube 11 thus formed. (Fig. 12.) It will be seen that this method will also be instrumental in providing a firm connection between flange and tube. The groove 3a is produced by means of a die I, pressed from the outside against the flange in the axial direction of the bobbin, said die being provided with an annular projection correspending to the groove 3a, whilst the inward forclng of the channel is effected with the aid of the inner die 6 encasing the bobbin tube a. The two dies are advanced towards the flange simultaneby forming the groove-shaped indentation 3a in the top of the hat-shaped central part I of the flange b prior to inserting the tube end, as can be seen from Fig. 13. The channel intended to receive the end of the bobbin tube a, will be produced when making the flange. Thus, after placing the flange upon the end of the tube, in connection with which the latter is made to enter the channel formed by the walls I and 4, nothing else will be required but to bend the channel in an inward direction and flatten it, in connection with which the wall I of the hat-shaped flange part is firmly pressed against the tube-end a so that the channel will be closed on said end. The end of the tube will in this case, again be constricted, in which constriction the channel wall will engage in (see Fig. 14') fold may be bent slightly in an outward direction, when securing the flange to the end of the tube. In this casethe same final shape will essentially be attained as shown in Fig. 12.

The method in accordance with Figs. 13 and 14 is further distinguished from the method in accordance with Figs. 11 and 12 by the fact, that the flange b is made to consist of somewhat thick sheet metal, so that the flange does not requireto be subjected to a reinforcing process by turning over or rolling the outer edge. The metal sheet, forming the flange will be stretched or dilated at the points where the crease 2 or the groove 3a is formed, thus producing at the crease 2 and at the channel receiving the endof the tube, a slightly reduced thickness of wall, rendering it possible to bend the fold and the crease inwardly and outwardly with case.

It is a matter of course, that a large number of variations or modifications of the represented and described examples are possible within the limits of the-present invention, the new process being applicable not only to the manufacture of film bobbins, but also to the manufacture of other bobbins made from sheet metal, e. g. yarn bobbins.

I claim:

1. The method of uniting the flange ends and tubular bodies of bobbins which consists in bending a flange end to form an [annular channel, inserting an end of the tubular body in said channel, and closing the channel on the inserted end and crimping the tube'inwardly at the mouth of the channel to form a seat for the material at one side of the channel whereby to form a reverse bend at the end of the tubular body.

2. The method of uniting the flange ends and tubular bodies of bobbins which consists in bonding a flange end to form an annular channel, inserting an end of the tubular body in said channel, and closing the channel on the inserted end and crimping the tube inwardly at the mouth of the channel to form a seat for the material on the outer side of the channel whereby to form a' reverse bend at the end of the tubular body.

3. The method of uniting the flange ends and tubular bodies of bobbins which consists in forming an annular channel in a flange end with the outer wall of the channel projecting below the inner wall of the channel, inserting a body end in said channel, and closing the channel on the inserted body end and forcing the channel outwardly and the outer wall of the channel in wardly to crimp the tube inwardly at the mouth of the channel whereby to form a reverse bend at the end of the tubular body.

4. The method of uniting the flange ends and tubular bodies of bobbins which consists in bending a flange end to form an annular channel, inserting an end of the tubular body in said channel, and in an outwardly flaring manner closing the channel on the inserted end and crimping the tube at the mouth of the channel to force the material inwardly and to form a seat for the material at one side of the channel If required, also the wall 4 of the whereby to form a reverse bend at the end of the tubular body.

5. The method of uniting the flange ends and tubular bodies of bobbins which consists in forming an annuar channel in a flange end with the outer wall of the channel projecting below the,

inner wall of the channel, inserting a body end in said channel, and'closing the channel on the inserted body end in an outwardly flaring manner and forcing the outer wall of the channel inwardly to crimp the tube inwardly at the mouth of the channel to form a reverse bend insaid tubular body.

6. The method of uniting the flange ends and tubular bodies of bobbins which consists in formring an outwardly flaring annular channel in a flange end with the outer wall of the channel projecting below the inner wall of the channel, inserting a body end in said channel, and closing the channel on the inserted body end and forcing the outer wall of the channel inwardly to crimp the tube inwardly at the mouth of the channel.

7. The method of uniting the flange ends and tubular bodies of bobbins which consists of bending a flange end to form an outwardly projecting hollow central portion surrounded by a marginal portion and having an annular wall and a head at its outer end, creasing the marginal portion around the central portion to form a channel opening inwardly and having its outer annular wall projecting inwardly beyond the general plane of the marginal portion, fitting an end of the tubular body into the central portion of the flange end, and applying pressure longitudinally of the body to flare the end of the body into the channel and then flatten out the crease about the central portion and cause the marginal portion to crimp the body adjacent the flared portion thereof and tightly grip the same.

8. The method of uniting the flange ends and tubular bodies of bobbins which consists of bending a disk to form a cup-shaped central portion open at its inner end and surrounded by a marginal portion having a portion extending at an outward incline from walls of the central portion, forming the central portion with a circumferentially extending "channel flaring outwardly and bordered by the inclined portion of the mar ginal portion, forcing an end of a tubular body into the channel by pressure exerted longitudinally of the body and form the body with a flared end seated in the channel, and continuing the pressure to flatten the inclined portion of the flange end and cause the same to crimp the body inwardly and tightly grip the same adjacent the flared end portion thereof.

9. The method of uniting the flange ends and tubular bodies of bobbins which consists of bending a disk to form a cup-shaped central portion open at its inner end and surrounded by a marginal portion having a portion extending at an incline from walls of the central portion, fitting an end portion of a tubular body into the central portion of the flange end, applying pressure longitudinally of the body to project the head of the central portion into the end of the body and constrict the walls and inclined portion of the marginal portion of the flange end about the body to form the flange end with an annular channel and the body with a flared end seated in the channel with portions of the body adja-' cent its flanged end crimped inwardly and tightly gripped by the constricted walls of the central portion of thezfiange end.

10. The method of uniting the flange ends and tubular bodies of bobbins which consists in bending a. flange end to form an annular channel opening inwardly and projecting outwardly from "the flange end and flared outwardly, applying flare the end of the body and force the same into the flared channel, and continuing the pressure to bend the channel and inserted end portion of the body whereby the walls of the channel will be forced into tight gripping engagement with the flared end portion of the body.

PHILIPP SCHWARZ. 

